Exposure calculating apparatus

Abstract

An exposure calculating apparatus includes a light-metering device, consisting of a light-metering elements corresponding to elementary areas obtained by dividing a field of a focusing optical system, for measuring a light intensity distribution in the field, a position of object detecting means for detecting a position of object in the field, a classifying means for changing a divisional pattern of light-metering areas in correspondence with the position of object, and classifying the light-metering elements of the light-metering device into a plurality of groups according to the divisional pattern, and a calculating device for calculating an exposure value by weighting the outputs from the plurality of light-metering elements in correspondence with the groups to which the light-metering elements belong, and supplying the exposure value to exposure control.

What is claimed is: 
     
       1. A camera comprising: visual axis detecting means for detecting a position of visual axis of a photographer in a field caught by a focusing optical system as a position of object;   light-metering means for measuring a light intensity distribution in the field;   tracking means for obtaining a position of object in the field on the basis of the light intensity distribution obtained by said light-metering means and the position of visual axis obtained so far, and tracking the position of object;   deciding means for deciding whether or not detection of the position of visual axis by said visual axis detecting means is possible; and   selecting means for selecting one of the positions of object obtained by said visual axis detecting means and said tracking means according to a decision result from said deciding means.   
     
     
       2. A camera according to claim 1, wherein said light-metering means measures the light intensity distribution in the field in units of a plurality of color components, and said tracking means tracks the position of object on the basis of color information obtained from the intensity distributions of the color components.   
     
     
       3. A camera according to claim 1, further comprising: first extracting means for extracting a light-metering result corresponding to at least one area of the field from an output from said light-metering means according to the position of object selected by said selecting means, and supplying the extracted light-metering result to exposure control; and   exposure controlling means for calculating an exposure value conforming to an object according to the input light-metering result, and performing exposure adjustment according to the exposure value.   
     
     
       4. A camera according to claim 1, further comprising: focus discriminating means for discriminating a focus state of an optical image corresponding to an object indicated by the position of object obtained from said selecting means; and   focusing control means for adjusting a focal point position of said focusing optical system according to a discrimination result from said focus discriminating means.   
     
     
       5. A camera according to claim 1, wherein said tracking means comprises first fuzzy calculating means for calculating a degree of conformity for an if-part that each position in the field is a position of object, and supplying the degree of conformity to tracking processing of an object. 
     
     
       6. A camera according to claim 1, further comprising: second fuzzy calculating means for calculating a degree of conformity for an if-part that each position in the field is included in an object on the basis of the position of object obtained from said selecting means and the light-metering results from said light-metering means;   second extracting means for extracting the light-metering result corresponding to an object portion on the basis of the degree of conformity, and supplying the extracted light-metering result to exposure control; and   exposure controlling means for calculating an exposure value conforming to an object according to the input light-metering result, and performing exposure adjustment according to the exposure value.   
     
     
       7. A camera according to claim 1, further comprising: second fuzzy calculating means for calculating a degree of conformity for an if-part that each position in the field is included in an object on the basis of the position of object obtained from said selecting means and the light-metering results from said light-metering means;   weighting means for weighting the corresponding light-metering result using the degree of conformity, and supplying the obtained light-metering result to exposure control; and   exposure controlling means for calculating an exposure value conforming to an object according to the input light-metering result, and performing exposure adjustment according to the exposure value.   
     
     
       8. An object perceiving apparatus comprising: object perceiving means for obtaining a position gazed by a photographer in a field of a camera as a position of object on the basis of movement of an eyeball of the photographer;   tracking means for discriminating a position corresponding to an object on the basis of information associated with a light intensity distribution in the field, and tracking the position;   deciding means for comparing the position obtained by said object perceiving means with the position obtained by said tracking means to as to decide whether or not the photographer changes an object;   selecting means for selecting one of the positions obtained by said object perceiving means and said tracking means according to a decision result from said deciding means; and   controlling means for controlling tracking processing by supplying the position obtained by said object perceiving means as information associated with a new object to said tracking means according to a decision result indicating that an object is changed.   
     
     
       9. An apparatus according to claim 8, wherein said tracking means sets the position obtained by said object perceiving means as an initial position of an object, and discriminates the position corresponding to the object on the basis of optical information at the initial position. 
     
     
       10. An apparatus according to claim 8, further comprising: brightness discriminating means for discriminating a brightness value at each position in the field on the basis of a light intensity distribution in the field, and supplying the brightness value to tracking processing by said tracking means, and   wherein said tracking means discriminates a position having a brightness value approximate to a brightness value of the object, and tracks the position.   
     
     
       11. An apparatus according to claim 8, further comprising: color discriminating means for discriminating a color at each position in the field on the basis of a light intensity distribution in the field, and supplying the color to tracking processing by said tracking means, and   wherein said tracking means discriminates a position having a color approximate to a color of the object, and tracks the position.   
     
     
       12. A camera comprising: an object perceiving apparatus of claim 8; and   exposure calculating means for receiving information associated with a light intensity distribution in a field, and a position of object selected by said selecting means, calculating an exposure value using brightness information indicating brightness at the position of object, and supplying the exposure value to exposure control.   
     
     
       13. A camera comprising: an object perceiving apparatus of claim 8; and   focus discriminating means for receiving information associated with a light intensity distribution in a field, and a position of object selected by said selecting means, discriminating a focus state of an optical image corresponding to an object indicated by the position of object, and supplying a discrimination result to focusing control.